Thermic telephone.



vPN'TI-R DE LANGE L ROBERTAEHNOUT BARON VAN I YNDEN.

THERMC TELEPHONE.

A1 PL1CAT10N FILED Nov. 4, 1915.

1200470. Patented 001:.. 10,1916.

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UMTED STATES PATENT OFFICE.

PIETER DE LANGE ANI) `ROBERT AERNOUT BARON VAN LYNDEN, 0F UTRECHT, NETHER- LANDS, ASSIG-NORS T0 NAAMLOOZE VENNOOTSCHAP DE NEDERLANDSCI-IE THERMO- TELEPHOON MAATSCHAPPIJ, OF UTRECHT, NETHERLANDS, A CORPORATION OF NETHERLANDS.

THERMIC TELEPHONE.

Application led November 4, 1915.

To all whom t may concern.

Be it known that we, PIETER DE LANGE and ROBERT AERNOUT BARON VAN LYNDEN, both subjects of the Queen of the Netherlands, and residing at Utrecht, in the Netherlands, have invented a. new and useful Thermic Telephone, of which the following is a specification.

This invention relates to thermic telephones, and has for its object to provide a thermic telephone in which the intensity of reproduction of the sound can be regulated as required. This object is attained .by thev -trated by way. of example in the accompanying drawing which shows the improved therniic telephone in vertical section, partly in elevation, drawn to an enlarged scale.

The thermic telephone illustrated comprises a tubular casing 1 which isclosed at both ends by means of cap or plug-like covers 2and 3 screwed into it. Within the tubular casing, heating conductor units are accommodated, each unit consisting of a suitable support 4 fitting the interior of the casing, and a group of heating conductors 5 mounted On each support 4. These-heating conductor units are loosely inserted into the casing 1 and held at the necessary distance apart, by means of preferably exchangeable distance rings 6. For the passing of the sound Waves, each of the supports 4, With the exception of the lowest one, is provided with an opening 7 preferably arranged in the center. The interior of the upper cover 2 forms the sounding chamber 8. The heating conductor group 5 adjoining the sound chamber 8 is covered by an annular protective hood 9 the cross-section of which conforms to that of the arch-shaped con- Specication of Letters Patent.

Patented Oct. 10, 1916.

Serial No. 59,621.

sages 7. The hood may also be provided at the top with sound openings 11.

The superimposed groups of heating con-I ductors are firmly held in the casing by means of the screw plug 3. This plug supports a disk 12 which in its turn engages the first ring G on whichrests the rst support 4 etc. up to the hood 9 which is held by the edge of cup 8.

The current conductors .13 14 are carried through the central opening 15 of the cover 3 and through `the annular disk 12. Their ends are connected to hollow contact studs 16, 17 inserted into the lowest support 4. Pins 18, 19 of the next higher support 4 engage with the bores of the hollow contact studs 16, 17 an electric connection thus being Obtained between the'tWo lowest heating conductor groups. The other heating conductor groups 5 are electricallyv connected together in the same manner.

In the construction illustrated the upper end of the cover 2 is provided with a connecting. branch 20 for a exible tube 21 leading to a sound receiver 22 intended toside by side in one and the same casing, en-

ablesv the number of the heating conductors to be modified easily to suit the requirements of the telephone. user. l

The hood 9 tting the shape of the archshaped heating conductors and'adjoining the Outer sound chamber 8, not only insuresa favorable transmission of the sound Waves of the uppermost heatin conductor group 5, but also protects as ar as possible the whole series ofthe heating conductors from penetration of dust or dirt particles or the like through the opening of cover 2.

The shape and arrangement of the heating conductors, as Well as the method of securing them to their supports, is immaterial for the invention. The heating conductor groups maybe arranged either in seresor in parallel connection, or in I nixed connection.

by side in said casing, and means We claim:

l. el tliermic telephone, comprising a casing, `groups of heat conductors superimposed in said casing, and means for electrically connectingsaid groups, said groups being adapt ed to be readily removed from said casing,

2. A thermic telephone, comprising a c asing, groups of heat conductors arraneed side ibielectrically connecting said groups, said'groups being adapted'to be readily removed from said casing.

fi thermic telephone, comprising in combination., a lcasing, means for closing both ends of said casing, and a plurality 'of heating conductor units within said casing, said units being held in position by said inea-ns for closing the ends oit said casing.

4, A thermic' telephone as described, corn-v prising in combination, a casing of tubular shape, a plurality of heating conductor units loosely inserted within said casing, plugs on either end of said casing, said plugs being adapted to hold in position said plurality of heating conductor units., v

- 5. A thermic telephone as described, comprising in combination, a tubular casing, a plurality of heating units loosely i' 1"ting into said casing, distance members ,n into said casing and adapted to ced between two successive units, means for electrically connecting said units, one means for closing the ends of said casing for firmly holding said units and said distance rings in positiona 6. A thermic telephone as described, comprising in combination, a tubular casing, a plug at one end of said casing, a hollow cover at the other end of said casing, an opening in said hollow cover, a. plurality of heating conductor units within said casing, each unit consisting oi a group of heating conductors and a support therefor, distance rings placed between each two adjoining supports, contact studs on one ois-aid suppi rts and sockets on the adjoining support, and means for connecting the contact studs of the lowest support to the current conductors.

7. A thermic telephone as described, comprising in combination, a tubular casing, a

@spies of this patent-.may be obtained for:

detachable plug for closing one end of said casing and having a passage for the current conductors, a hollow cover detachably secured to the other end of said casing and having a passage for the sound waves, a plurality of superimposedheating conductor units within said casing between said plug and said hollow cover, each of which units consists of a group of heating conductors and a support for the same, said supports being provided with sound passages, distance rings between two adjoining supports, a distance ring beneath the lowest support, a protective hood for the heating conductor group of the top unit, a central sound passage in said hood, means for electrically connecting'- the heating conductor units, and means for velectrically connecting at least one heating Aconductor unit to the current conductors.

8. A thermic telephone as described, comprising in combination, a casing, a plurality of heating conductor units within said casing, each of which units is adapted to be readily removed from. said casing, means for closing the ends of said casing, saidfmeans being adapted to hold said plurality of units in position, a passage for the sound waves in one of said means for closing the ends o said casing, a flexible tube communicating with said passage, a receiver at the termination of said tube adapted to be introduced into the human ear, means for conductively connecting said heating conductor units when in position within said casing, and means forl conductively connecting at least one of said heating conductor units with the current conductors.

9. In a thermic telephone, in combination, a plurality of heating conductor units each of which is adapted to be readily removed from said casing, means for conductively connecting said units, said means becoming operative on said units being placed inposition within the telephone casing, and means for conductively connecting .at least one of said units to the current conductors. ln testimony whereof we have signed this specification.

PlE'lER DE LANGE. ROBERT AERNOUT BARON VAN LYNDEN.

five cents each, by addressing the Commissioner of latentl. Washington, D. C.

so y 

